Renesas M16C User Manual

Rev.1.10    Jul 01, 2005    page 219 of 318
REJ09B0124-0110

M16C/6N Group (M16C/6NK, M16C/6NM)

18. CAN Module

This document is under development and its contents are subject to change.

The acceptance filter support unit has a function to judge valid/invalid of a received ID through table search.

The IDs to receive are registered in the data table; a received ID is stored in the CiAFS register ( i = 0, 1),

and table search is performed with a decoded received ID. The acceptance filter support unit can be used

for the IDs of the standard frame only.

The acceptance filter support unit is valid in the following cases.

 • When the ID to receive cannot be masked by the acceptance filter.

(Example) IDs to receive: 078h, 087h, 111h

 • When there are too many IDs to receive; it would take too much time to filter them by software.

Figure 18.18 shows the write and read of the CiAFS register in word access.

 b15

b0

b8      b7

When read

SID10 SID9 SID8 SID7 SID6 SID5 SID4 SID3

SID10 SID9 SID8 SID7 SID6

SID5 SID4 SID3 SID2 SID1 SID0

When write

3/8 Decoder

242h

242h

Addresses

CAN0

244h

244h

CAN1

b15

b0

b8      b7